Maule M-5-180C N76RD accident near Marshfield, Massachusetts

Probable cause

A partial loss of engine power for reasons that could not be determined in postaccident examinations because fire damage precluded testing of the fuel and several engine accessories.

NTSB analysis

The pilot reported that the airplane departed with adequate fuel onboard (about 40 gallons) but that, about 400 feet above ground level, the engine lost partial power. Specifically, the rpm dropped to 1,500, and the engine began to "backfire." The pilot turned the airplane to avoid some houses and performed a forced landing into trees. After the impact, a fire ensued and consumed most of the wreckage. Subsequent examination of the engine and propeller governor did not reveal any preimpact mechanical malfunctions that would have precluded normal operation. Several engine accessories, including the magnetos and carburetor, could not be tested due to heat and impact damage. Additionally, no fuel samples could be tested because all of the fuel was consumed in the fire. The reason for the partial loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for ERA14LA043 for the full record.